First global antineutrino emission map highlights Earth's energy budget

September 1, 2015, University of Maryland
The first-ever global map of antineutrino flux, which accounts for natural and human-made sources of antineutrinos, with the latter making up less than 1 percent of the total flux. Credit: National Geospatial-Intelligence Agency/AGM2015

The neutrino and its antimatter cousin, the antineutrino, are the tiniest subatomic particles known to science. These particles are byproducts of nuclear reactions within stars (including our sun), supernovae, black holes and human-made nuclear reactors. They also result from radioactive decay processes deep within the Earth, where radioactive heat and the heat left over from the planet's formation fuels plate tectonics, volcanoes and Earth's magnetic field.

Now, a team of geologists and physicists has generated the world's first global map of antineutrino emissions. The map, published online in the journal Scientific Reports on September 1, 2015, provides an important baseline image of the energy budget of Earth's interior and could help scientists monitor new and existing human-made sources of radiation. The study was led by the National Geospatial-Intelligence Agency with contributions from researchers at the University of Maryland, the University of Hawaii, Hawaii Pacific University and Ultralytics, LLC.

"The interior of Earth is quite difficult to see, even with modern technology. Locating the activity of antineutrinos allows us to create images that our predecessors had only dreamed of," said William McDonough, professor of geology at UMD and a co-author of the study. "This map should prove particularly useful for future studies of processes within the lower crust and mantle."

Neutrinos are notoriously difficult to study; their tiny size and lack of electrical charge enables them to pass straight through matter without reacting. At any given moment, trillions of neutrinos are passing through every structure and living thing on Earth. Luckily, antineutrinos are slightly easier to detect, through a process known as inverse beta decay. Spotting these reactions requires a huge detector the size of a small office building, housed about a mile underground to shield it from cosmic rays that could yield false positive results.

In the current study, the team analyzed data collected from two such detectors—one in Italy and one in Japan—to generate a picture of antineutrino emissions from natural sources deep within Earth. They combined this with data collected by the International Atomic Energy Agency (IAEA) on more than 400 operational nuclear reactors. In total, antineutrinos from these human-made sources accounted for less than 1 percent of the total detected.

"Keeping tabs on nuclear reactors is important for international safety and security. But as a geologist, I'm particularly excited for the potential to learn more about Earth's interior," McDonough said. "This project will allow us to access basic information about the planet's fuel budget across geologic time scales, and might yet reveal new and exciting details on the structure of the deep Earth."

The team plans to make periodic updates to the global antineutrino map in the future, with the help of improved models of Earth's interior and enhanced antineutrino detection technology. Updates to the map will also reflect the construction and decommission of nuclear reactors as appropriate. All told, the maps will provide an up-to-date picture of Earth's overall radioactivity.

"Antineutrinos are only one particle produced by Earth's natural radiation," explained Shawn Usman, R&D Scientist at the National Geospatial-Intelligence Agency and lead author of the study. "The National Geospatial-Intelligence Agency is working with UMD to develop additional radiation maps to characterize the Earth's naturally-occurring gamma and neutron radiation."

Explore further: Team records neutrinos from the Earth's mantle

More information: The research paper, "AGM2015: Antineutrino Global Map 2015," Shawn Usman, Glenn Jocher, Stephen Dye, William McDonough and John Learned, was published online September 1, 2015 in the journal Scientific Reports. www.nature.com/articles/srep13945

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21 comments

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antialias_physorg
5 / 5 (19) Sep 01, 2015
I dunno about you guys, but reading something like "antineutrino emission map" sounds totally (and awesomely) SciFi to me.

"Captain, I've scanned the antineutrino signature of that planet. It looks like we found something interesting"
El_Nose
5 / 5 (3) Sep 01, 2015
@ant

it sounds fishy to me... as this was mainly taken from one detector and combined with a map of known nuclear reactor sites. If it was totally accurate you would expect Chernobyl in northern Ukraine to show up as a hot spot.
cjones1
5 / 5 (4) Sep 01, 2015
Can it be used to detect the Iranian enrichment facilities?
Tektrix
5 / 5 (4) Sep 01, 2015
Can it be used to detect the Iranian enrichment facilities?


It might: http://spectrum.i...-reactor
SciTechdude
5 / 5 (4) Sep 01, 2015
@ant

it sounds fishy to me... as this was mainly taken from one detector and combined with a map of known nuclear reactor sites. If it was totally accurate you would expect Chernobyl in northern Ukraine to show up as a hot spot.


It sort of does. If you look north of the red blob of turkey, there's a bunch of deeper reds around Ukraine.
docile
Sep 01, 2015
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docile
Sep 01, 2015
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axemaster
5 / 5 (6) Sep 01, 2015
I dunno about you guys, but reading something like "antineutrino emission map" sounds totally (and awesomely) SciFi to me.

"Captain, I've scanned the antineutrino signature of that planet. It looks like we found something interesting"

Yeah, I thought this was a joke at first. I had no idea that they could detect enough of them to do something like this.
docile
Sep 01, 2015
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docile
Sep 01, 2015
This comment has been removed by a moderator.
JustAnotherGuy
not rated yet Sep 01, 2015
If it was totally accurate you would expect Chernobyl in northern Ukraine to show up as a hot spot.
It sort of does. If you look north of the red blob of turkey, there's a bunch of deeper reds around Ukraine.

Can this help improve speculations/conclusions? :
https://upload.wi...ment.svg
http://www.nature...igures/1
(note the Black Sea looks as redish as any country)
axemaster
5 / 5 (1) Sep 01, 2015
So... it was a joke?

What the heck is this map then? Simulated data?

Read some more comments... so it is a model. Physorg, uh, this is kind of misleading. Can we fix this, or change the legend under the picture or something?
JustAnotherGuy
5 / 5 (1) Sep 01, 2015
"Captain, I've scanned the antineutrino signature of that planet. It looks like we found something interesting"

Good one!
Somewhat, they made implications on this perspective in their paper (article's reference). Probably this has nothing to do with "accuracy" but does with emissions.
Every second greater than 10^25 antineutrinos radiate to space from Earth, shining like a faint antineutrino star.

Intriguing...
EyeNStein
5 / 5 (2) Sep 01, 2015
Its a composite map of detected background anti-neutrinos (the vague fuzzy areas) and hot spots provided by the IAEA. Which explains why Saudi Arabia has the only middle eastern hotspot when there should be others.
Perhaps this will be more useful with more underground detectors with better angular resolution. But then the CIA and NSA wouldn't let us see the results.
rpaul_bauman
not rated yet Sep 02, 2015
Well; I still am in luck. They completely missed my anti-neutrino generator as a hot spot.. Which makes me feel like they nor any one else knows about it !!! I'm right, right, you don't know about it ?
TechnoCreed
not rated yet Sep 02, 2015
For those who would like to view that on Google Earth click on my link and clck on the file when it is fully downloaded. https://www.nga.m..._Map.kmz
EyeNStein
not rated yet Sep 02, 2015
This could be the heart of the CIA's secret anti-neutrino homing torpedo.
If only its sensing system wasn't the size of a house and its guaranteed accuracy wasn't >100 miles from any soviet nuclear powered target submarine.
KeithMcC
not rated yet Sep 02, 2015
Aside from reactors there is the dark blob in Tibet. What is that?
EyeNStein
5 / 5 (2) Sep 02, 2015
"Granitic melts derived from the subducting Indian crust rise into the overlying Eurasian and transfer heat into the base of the Tibetan Plateau. The resulting thickened crust is heated by radioactive decay of the element potassium, uranium, and thorium, which are preferentially concentrated in the magmas." This fission decay generates ant-neutrinos.
http://oak.ucc.na...eau.html
KeithMcC
not rated yet Sep 02, 2015
"Granitic melts derived from the subducting Indian crust rise into the overlying Eurasian and transfer heat into the base of the Tibetan Plateau. The resulting thickened crust is heated by radioactive decay of the element potassium, uranium, and thorium, which are preferentially concentrated in the magmas." This fission decay generates ant-neutrinos.
http://oak.ucc.na...eau.html

I don't understand how this mechanism concentrates potassium, uranium, and thorium in this geographical area.
EyeNStein
5 / 5 (1) Sep 03, 2015
Hi Keith. Its down to relative insolubility of Uranium and thorium minerals in molten rock. Try reading this wiki:-
https://en.wikipe..._genesis

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